Black Hole Masses and Eddington Ratios of AGNs at z < 1: Evidence of Retriggering for a Representative Sample of X-Ray-selected AGNs

WeestimatedblackholemassesandEddingtonratiosforasampleof X-ray-selectedactivegalacticnuclei(AGNs) inthefieldscoveredbytheGreatObservatoryOriginsDeepSurvey(GOODS).Thespannedrangesinredshift(0:4 < z < 1) and hard X-ray luminosity(10 42 PLX P4 ; 10 43 ergss � 1 )allowus tostudy arepresentative subsampleofthe main contributors to the 2Y10 keV X-ray background. Nuclear and bulge magnitudes in four bands have been measured via a two-dimensional decomposition applied toHSTACS images. Using the black hole versus bulge luminosity relation and the intrinsic nuclear emission, we derived the black hole mass and the AGN bolometric luminosity. Wefindinoursamplethat(1)theX-rayYtoYopticalindicesarelargerthaninopticallyselectedQSOs,asexpecteddue to the X-ray selection); (2) the X-ray bolometric corrections are generally small, suggesting a decrease with the nuclear luminosity; (3) the Eddington ratios are about a factor 10 below the values found at higher redshift and luminosity; (4) the central black holes have rather largemasses; and (5) at least for z P0:8, a scarceness of black holes with